Scratch 'n Sneeze - Science of Allergies

This week's Naked Scientists is not to be sneezed at - we're looking at the science of allergies! We explore what happens to cause your body to overreact to harmless things, and find out how potentially fatal peanut allergy can be cured. Plus, how a dose of parasites could keep allergies at bay, and how special filters can engineer a breath of extremely fresh air!